Protective captivating collar



E. W. DOWNS 12204222262 Eaves? Wflowm, A 11 *M. A?

Filed June 27, 1966 Dec. 5, 1967 PROTECTIVE CAPTIVATING COLLAR United States Patent 3,355,977 PROTECTIVE CAPTIVATING COLLAR Ernest W. Downs, Natick, Mass, assignor to the United States of America as represented by the Secretary of the Army Filed June 27, 1966, Ser. No. 561,667 Claims. (CI. 85-8.1)

ABSTRACT OF THE DISCLOSURE A protective captivating collar for a lanyard and more particularly to a collar for attaching a captivating lanyard for a locking pin to a collapsible frame structure and protecting the lanyard from physical damage.

Captive locking pins have been used for locking various types of telescoping or hinged collapsible structures. It has been customary to provide such pins with chains or lanyards to prevent loss thereof when they are withdrawn from the holes in which they fit while locking the collapsible structures. These chains or lanyards are usually attached to the collapsible structures by means of screws, clamps, hooks or similar fastening devices.

In recent years, radar equipment has been widely used by the Armed Forces to detect the presence of aircraft or missiles. This equipment requires shelter, which is usually made collapsible to facilitate moving the radar equipment to different locations. If any parts of the shelter are metallic, microarcing occurs and interferes with radar reception. Accordingly, it is necessary for all ele ments of such shelters to be non-metallic such that various plastic materials have been used for the structural members and synthetic textile cord has been used to secure the locking pins to the related frame elements. The manner of securing the cord to the frame elements has presented a difiicult problem. Non-metallic fittings such as projecting loops and eyes are easily damaged during assembly, disassembly and transport of the frame elements while simply tying the cord around the frame subjects the cord to abrasion and/ or cutting action against the relatively hard surface of the frame element during stowage and transport of the frame elements.

It is therefore an object of the present invention to provide a simple, rugged means for attaching an elongated flexible element to a collapsible frame member.

A further object is to provide attaching means which afford a substantial degree of protection against damage to a lanyard or cord where it is attached to a collapsible frame member.

Other objects and advantages of the invention will appear from the following description of one embodiment of the invention, and the novel features will be particularly pointed out in connection with the appended claims.

In the accompanying drawing:

FIGURE 1 is a plan view of a collapsible frame member of a portable structure having locking joints, showing a removable locking means held captive by an elongated flexible element attached thereto and to the frame member by a protective captivating collar in accordance with the invention;

FIGURE 2 is a plan View similar to FIGURE 1 but showing the removable locking means locking the collapsible frame member in an extended condition from that shown in FIGURE 1;

FIGURE 3 is a cross-section taken along the line 3-3 of FIGURE 1; and

FIGURE 4 is a plan view of the protective captivating collar of the invention prior to assembly thereof with the elongated flexible element and the collapsible frame member, the view being taken from a position above the collar ICC as it is shown in FIGURES 1-3, showing an opening in the sidewall of the collar and a groove in the inner surface of the collar, the purpose of which will be explained hereinafter.

Referring specifically to the drawing wherein like characters designate like parts in all views, 10 designates generally any suitable collapsible frame member, such as a telescoping frame member of a portable shelter, comprising an outer tubular frame member 11 and an inner rod-shaped frame member 12 in telescoping relation With outer frame member 11. The outer frame member 11 has a pair of holes 13 and 14 in its sidewall radially spaced at diametrically opposed points therein and longitudinally spaced from a first end 15 of the outer frame member, the holes being sized to receive a removable locking pin 16 in snug-fitting relation. The inner frame member 12 has a first hole 17 passing diametrically therethrough and spaced from a first end 18 thereof, hole 17 being sized to receive the removable locking pin 16 in snug-fitting relation and being located to be aligned with holes 13 and 14 of outer frame member 11 to provide for insertion of locking pin 16 through holes 13, 17 and 14 to lock the frame member in a first position. The inner frame member 12 also has a second hole 19 passing diametrically therethrough and spaced longitudinally along the inner frame member from hole 17. Hole 19 is also sized to receive the removable locking pin 16 in snug-fitting relation and located so as to be aligned with holes 13 and 14 of outer frame member 11 to provide for insertion of locking pin 16 through holes 13, 19 and 14 to lock the frame member in a second or extended position.

To prevent accidental loss of locking pin 16, particularly when the frame member is unlocked and collapsed, an elongated flexible element, such as a nylon cord 20, is attached to one end of the locking pin by being threaded through hole 21 passing through one end of the locking pin, the nylon cord being knotted adjacent to each end of hole 21. The nylon cord is attached to the outer frame member 11 by captivating collar 22.

Collar 22 comprises a short length of hollow tube which closely engages the outside surface of the outer frame member 11. As shown in FIGURE 3, collar 22 is provided with a groove 23 formed in its inner surface 24 extending substantially completely around the inner circumference thereof. Groove 23 is formed to a depth and configuration to receive the nylon cord 20 therein. An opening 25 is provided in the sidewall of collar 22 extending from its outer surface 26 at least to the bottom of groove 23 and preferably completely through the sidewall. The opening 25 is sized to receive at least two thicknesses of nylon cord 20 and preferably sized to receive a knot 27 tied in nylon cord 20 therein.

In the use of the invention, the nylon cord 20, which is attached at one end to locking pin 16 as described above, is fed through opening 25 in the collar, around the inner periphery of the collar, being positioned in groove 23, and back out through opening 25. The collar is then fitted over outer frame member 11 and cemented in place a short distance from holes 13 and 14 in said outer frame member such that the segment 28 of the nylon cord between locking pin 16 and the opening 25 is of sufiicient length to permit the locking pin to be readily inserted into or removed from holes 13 and 14. Knot 27 is then tied in-nylon cord 20 to prevent the nylon cord from being accidentally pulled out of the groove 23. The nylon cord may be cut beyond the knot at any suitable point, but preferably at a point which provides an auxiliary segment 29 of the nylon cord for attachment to locking pin 16 in place of segment 28 if the latter should be severed. Knot 27 may be formed within opening 25 or it may be forced thereinto to protect it from 3 a rasion dama e Thi the ylon co di lq ped around the outer frame member and is held captive by the protective captivating collar 22. The portions of the nylon cord within the groove 23 are protected against physical damage by abrasion orother means.

All of the :parts of the above-described collapsible frame may be made of non-metallic materials, such as plastics, :for use in shelters for radar equipment or as elements of collapsible supports or otherwise in association with radar equipment. This is especially important because of the tendency of metallicelements to produce microarcing. However, it is to be understood that the protective captivating collar as well as the lanyard may be constructed of metal for uses in which metals will causeno interference withthe performance of the equipment with which the captivating collar and lanyard are used.

The protective captivating collar of the invention provides a very simple, rugged and effective means for attaching a captivating lanyard for a locking pin of a collapsible tubular or rod-type frame to the frame and simultaneously protecting the lanyard against physical damage. The knot by means of which the lanyard is tied to the tube or rod of the frame may be protected by being recessed within the hole in the collar which provides access to the interior circumferential groove in the collar within which a loop of the lanyard passes around vthe tube or rod. This device is-al so advantageous in terms of safety for personnel using collapsible frames since it eliminates sharp-edged elements commonly used for fastening captivating lanyards or chains to such frames. It will be understood that various changes in the details,

,materials and arrangement of parts, which have been herein described and illustrated in order to explain the nature of the invention, may be made bythose skilled in the art, within the principle and scope of the invention as expressed in the appended claims.

I claim:

1. In a portable structure comprising collapsible frame members with locking joints and removable locking means for locking said joints, said locking means being held captive by elongated flexible elements attached thereto and to said frame members, that improvement therein which comprises a protective captivating collar for maintaining each of said elongated flexible elements connected to a frame member and protected against damage, said collar being snugly received on a portion of said frame member and having ,a groove .in the inner surface thereof passing substantially completely around said inner surface, said groove having across-sectional QOnfiguration substantially corresponding to that of said flexible element, said elongated flexible element being received within said groove, said collar having an open ing in the sidewall thereof extending from its outer surface to the opposed ends of said groove forming a continuous passage therewith from the outside of said collar and around said frame member and means constraining said collar from removal from said frame member whereby said elongated flexible element :18 .passed through said opening in said collar, around said frame member, and back out'through said opening and secured against withdrawal from said opening thereby securing said element to said frame member.

2. The-improvement according to claim 1 wherein one end of said elongated, flexible retaining element vis .provided with means to prevent said one end from being drawn through said opening in said collar and the other end of said elongated, flexible retaining element is fixed to said removable locking means.

3. The improvement according to claim 1 wherein said elongated, flexible retaining element comprises a nylon cord, one end of which is passed through said opening, said passage around said frame member and back out through said opening and then attached to another portion of said cord outside of said :collar whereby said cord .is thereby attached to said frame member.

4. The improvementaccording to claim 1 wherein said groove in the inside surface of said protective captivating collar extends completely around the inside surface thereof and said opening in :the sidewall of said collar extends to the bottom of said groove.

.5. The improvement according to claim 1 wherein said captivating collar is .fixed to said frame member.

References Cited UNITED STATES PATENTS 992,383 5/1911 Paul 1'3'5--4 1,828,147 10/1931 Kamman 1375--3 2,687,268 8/ 1954 vHawes. 2,705,956 4/1955 Magary --.1 2,957,482 10 1960 Tomek 135-1 3,058,480 10/ 1962 Blanchard .135-1 3,061,343 10/ 19,62 Doyle 287-5.8 3,195,928 7/1965 'Pasternack ,2,85-321 3,323,826 6/1967 Crowley.

CARL W. TOMLIN, Primary Examiner.

S. BR-ITTS, Assistant Examiner. 

1. IN A PORTABLE STRUCTURE COMPRISING COLLAPSIBLE FRAME MEMBERS WITH LOCKING JOINTS AND REMOVABLE LOCKING MEANS FOR LOCKING SAID JOINTS, SAID LOCKING MEANS BEING HELD CAPTIVE BY ELONGATED FLEXIBLE ELEMENTS ATTACHED THERETO AND TO SAID FRAME MEMBERS, THAT IMPROVEMENT THEREIN WHICH COMPRISES A PROTECTIVE CAPTIVATING COLLAR FOR MAINTAINING EACH OF SAID ELONGATED FLEXIBLE ELEMENTS CONNECTED TO A FRAME MEMBER AND PROTECTED AGAINST DAMAGE, SAID COLLAR BEING SNUGLY RECEIVED ON A PORTION OF SAID FRAME MEMBER HAVING A GROOVE IN THE INNER SURFACE THEREOF PASSING SUBSTANTIALLY COMPLETELY AROUND SAID INNER SURFACE, SAID GROOVE HAVING A CROSS-SECTIONAL CONFIGURATION SUBSTANTIALLY CORRESPONDING TO THAT OF SAID FLEXIBLE ELEMENT, SAID ELONGATED FLEXIBLE ELEMENT BEING RECEIVED WITHIN SAID GROOVE, SAID COLLAR HAVING AN OPENING IN THE SIDEWALL THEREOF EXTENDING FROM ITS OUTER SURFACE TO THE OPPOSED ENDS OF SAID GROOVE FORMING A CONTINUOUS PASSAGE THEREWITH FROM THE OUTSIDE OF SAID COLLAR AND AROUND SAID FRAME MEMBER AND MEANS CONSTRAINING SAID COLLAR FROM REMOVAL FROM SAID FRAME MEMBER WHEREBY SAID ELONGATED FLEXIBLE ELEMENT IS PASSED THROUGH SAID OPENING IN SAID COLLAR, AROUND SAID FRAME MEMBER, AND BACK OUT THROUGH SAID OPENING AND SECURED AGAINST WITHDRAWAL FROM SAID OPENING THEREBY SECURING SAID ELEMENT TO SAID FRAME MEMBER. 